In an SDN, several remote sites may be linked together over a public network (such as the Internet) to provide a shared network fabric across several sites that are located in different physical spaces. Data may be transmitted within one site (i.e., as intra-site traffic) and may be transmitted over the public network from one site to a different site (i.e., as inter-site traffic). Traffic that travels from one site to another may be unicast by transmitting the data from one sending site to one receiving site, or may be multicast by transmitting the data from one sending site to several receiving sites. Several specifications use multicast traffic with inter-site traffic, but in light of network outages (e.g., spine reloads, buffer overloads, network congestion), are vulnerable to loops forming in the network fabric. Loops may result in network deadlock and other deleterious effects.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.